Plate pasteurizer

Plate pasteurizer

Plate pasteurizer or plate pasteurizer is a device that pasteurizes fluids such as milk and similar products. But why milk should be pasteurized, we will examine in the following. Milk and dairy products are important components of a healthy diet because they have many nutritional benefits. However, unpasteurized milk or dairy products can be a means of transmitting pathogenic microorganisms to the body. Various pathogenic microorganisms such as (Bacillus cereus), Salmonella spp., Listeria monocytogenes, Yersinia Enterocolitica (Yersinia enterocolitica), Escherichia coli O157: H7, and Campylobacter jejuni are sometimes found in dairy and livestock products.

Plate pasteurizer

A plate pasteurizer requires a lot of energy and money to heat and cool the liquid. In addition, prolonged heating of eggs, milk and fruit juices has a negative effect on the value and taste of nutrients. For this reason, modern devices are designed to optimize thermal processes in order to have a high quality pasteurized product and reduce operating costs as much as possible.

Application of plate pasteurizer or plate pasteurizer

Page pasteurizer, also known as pasteurizer (HTST) or pasteurization with high temperature and low time, is one of the equipment for killing pathogenic microorganisms that is specific to pasteurization. Large-scale unpackaged foods, including low-viscosity fruit juices (apple or orange juice), dairy products, beverages, egg products, etc., are designed and manufactured. In some food products, such as fruit juices, where oxidation may occur, such as apple juice, the oxygen in it is aerated and drained before the pasteurization operation.

The role of the plate in the operation of the pasteurizer (heat exchange)

High temperature and low time pasteurization (HTST) requires heating and subsequent rapid cooling of the milk. The products are heated and stored at a specific temperature and time. Rapid cooling is then performed to ensure complete eradication of pathogenic microorganisms.

One of the advantages of the system (HTST) is its low cost and high throughput. Using heating and re-cooling in heat exchangers can increase operating efficiency. Raw, cooled milk is heated by passing through stainless steel plates until the valve reaches 161 degrees Fahrenheit. It stays at this temperature for at least 15 seconds to kill the bacteria and quickly reach its initial temperature (39 degrees Fahrenheit).

HTST milk pasteurization with 90% heat recovery (heat recovery) (energy re-used) turns this equipment into an environmentally friendly system, meaning that milk Hot is used to heat cold milk before entering the pasteurized area.

is the most common type of high temperature short time pasteurization (HTST) that can be applied to plate pasteurizers. Heat treatment is performed using a plate heat exchanger. This piece of equipment consists of a group of corrugated stainless steel plates that are glued together in a frame. Washers that have a high resistance to high temperature are placed between them to prevent the mixing of liquids between the plates. These plates are made with a thickness of 95-125 mm.

What should be the quality of the pipes in the plate pasteurizer

Pages and frames of heat exchangers from stainless steel The valve and heating circuit are equipped with stainless steel pumps. The milk is heated slowly and indirectly by the heating system using hot water. The pasteurization unit includes all the necessary equipment for automatic milk pasteurization as well as an automatic control system and integrated temperature recorder.

Due to the passage of milk through the pipes in the pasteurizing machine, all the pipes of the pasteurizing machine must be made of high quality stainless steel and also all the welds of these pipes are done in a way that can be easily washed with the CIP machine.

What are the components of a plate pasteurizer:

Balance Tank ( Balance Tank )

This device is actually the interface of the raw milk storage tank and the pasteurizer, which regulates the raw milk entering the pasteurizer. This tank is equipped with a set of floating valves that level the liquid level. Controls almost constant and ensures uniform pressure on the product coming out of the tank. The overflow surface should always be below the minimum flow rate of the regenerator. Therefore, it helps to maintain more pressure on the pasteurized side of the heat exchanger. The balance tank also prevents air from entering the pasteurizer by placing the top of the outlet pipe below the lowest point in the tank and creating downward slopes of at least 2%.

Regenerator ( Regenerator )

Using the regenerator, pre-heat the cold raw milk with the heat that the hot pasteurized milk flows in the opposite direction. In this section, you can save the heating and cooling energy. .

This part separates the pasteurized and raw milk product with stainless steel plates.

Temperature exchanger ( heat exchanger )

Heat converter in plate pasteurizers consisting of a number of plates and sheets Stainless steel is square or rectangular in shape that can be easily washed. These plates are used as heaters, coolers, heat exchangers and storage tanks.

timing pump h

This device controls the flow rate in the system (HTST) and is located after the raw regenerative valve and before the retaining tube. Pulls and pushes it forward. Pasteurized product is always under more pressure than raw material.

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Common types of timing pumps are:

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Gear-driven positive displacement pump

In this type of pump, two rotors or gears rotate in an elliptical position to transfer fluid around the perimeter of the pump body. The temperature and type of fluid pumped may greatly affect the performance of the positive gear shift pump.

Piston-type pump, such as a homogenizer

This is a very efficient positive displacement pump and is commonly used as a timer pump in pasteurizers (HTST). centrifugal pump along with flow control methods.

Holding tube ( Holding tube )

Food is stored in a pasteurizer at a pasteurization temperature for a limited time. In the H.T.S.T method, food that has reached the pasteurization temperature is stored at the same temperature for a period of time. For example, milk that has reached a temperature of 72 ° C is stored for 16 seconds.

Temperature Controller ( Recorder-controller (STLR )

The thermometer represents the most accurate measurement of the temperature of hot milk, cooled milk and temperature control. This is the official temperature of the safety thermal limiter. recorder) it is set. (STLR) records milk temperature, time and day. Controls, monitors and records the position of the Flow Diversion Device. The controllers are pneumatic and electronic. This device adjusts the temperature of the incoming steam if it shows the temperature of the food more or less than usual.

Valve flow diversion valve

Also called a flow deflection valve (FDD), located at the lower end of the sloping retaining tube. It is a three-way valve that opens for forward flow at temperatures above 72 ° C. Foods that are at a temperature of less than 72 degrees Celsius and have not reached the pasteurization temperature, the outlet valve is automatically closed and the milk returns to normal and from the third path to the level container or the same side of the balance tank (Regeneration) Leads.

Types of plate pasteurizers and their applications

Pasteurizer Plate is one of the pasteurizers that can use the HTST method Run is a four-stage plate pasteurizer that consists of 4 interconnected plate converters. Plate pasteurizers consist of 4 parts: heat recovery, pasteurization part, cooling part and cooling part.

This machine heats the milk in three stages and brings it to the pasteurization temperature and cools it in three stages.

A plate pasteurizer consists of three parts:

– The first and main part of the pasteurizer device in which hot water flows.
– The second part in which the cooling of the milk is done with zero degree cold water.
– The third part of raw milk is heated only with pasteurized milk or with water and pasteurized milk.

The first and main part of the pasteurizer device in which hot water flows

In the first part, the liquid product (milk) is heated to pasteurization temperature. The heated milk then passes through a portion of the tubes to maintain the processing temperature and allow time for pasteurization.

The second part in which the milk is cooled with zero degree cold water

In the other part, the milk passes through the cooling part and cools down to +4 ° C. Raw milk enters the machine, the temperature of which is usually less than 10 ° C, while passing through the first part (first exchange) as soon as it passes by the hot milk pipes leaving the machine without mixing the two garlic together, its temperature reaches 40 It reaches 50 degrees Celsius.

In this part, the milk is directed to the separator at the right temperature to control fat and creaminess.

In this part, the cream is separated from the milk and stored for the next process.

Milk whose fat has been removed re-enters the pasteurization machine and during the passage of the second part (second exchange) due to the heat exchange of adjacent plates, its temperature is approximately 60 ° C. And goes to Homogenizer moves .

The best temperature for whipping and controlling milk fat is 60 ° C. In the next part, the homogenized milk is returned to the pasteurization machine and enters the third part of the machine (section).

The third part of raw milk is heated only with pasteurized milk or with water and pasteurized milk

In this part, the milk reaches the pasteurization temperature which is 72 degrees Celsius. After the pasteurization temperature, the milk moves along the tubes known as holding tubes (Holding Tiupe).

The length of these pipelines is adjusted so that the valve takes 15 to 16 seconds to reach the end of the pipe, and in this way the pasteurization operation is done well and the time required for Pasteurization takes place there and eventually passes through the control valve.

The milk at the end of this route is pasteurized and needs to be cooled. The valve loses half of its heat on the way to the second exchange and loses its temperature during the passage of the first exchange in the vicinity of the cold inlet valve.

During the second and first exchange, the temperature of the milk is 20 to 30 degrees Celsius. In the fourth part of the device, there is a plate pasteurizer or the same section as the cooling part, and in the vicinity of the device known as Ice Bank, by exchanging heat with very cold water, the temperature of which is close to zero, the valve loses its temperature and reaches 4 degrees Celsius. Arrives.